campbell has achieved what many young men dream of. he made it to the pros. injuries ended his nfl career but campbell successfully found a new life after the game as a real estate broker. >> welcome back to "life after the game." >> reporter: and radio talk show most on the voice america network a platform he uses to educate other players about transitioning to life after football as well as the dangers of injuries you can't see, repeated hits to the head. >> i don't think we thought that you had a concussion until you were knocked out on the field. >> reporter: as a player he didn't know that concussions can cause serious injury to the brain. now campbell says playing football takes years off a players' life. he's also suffered some memory loss. >> there were situations where i don't remember certain series. i would be out there and not realize exactly what was going on. >> reporter: while he was never diagnosed, looking back, campbell believes he's had over ten concussions in his football career and he believes players today need to